2.2.2
Coupling the hydraulic system
The hydraulic fan drive can be used for two types of
hydraulic tractor systems: an open system which includes a
gear pump with invariable oil supply and a closed system
which includes a piston pump with a variable oil supply. By
opening or closing of the cock (A, fig. 7) fitted to the control
block underneath the fan’s hydraulic motor, the drive can be
adjusted for an open or a closed system.
• Open system (gear pump): open the cock by turning it
completely to the left.
• Closed system (piston pump): close the cock by turning it
completely to the right.
• If you are unsure which type of hydraulic system is
mounted in your tractor contact your dealer.
• An incorrect adjustment of the drive may cause consi-
derable damage in the hydraulic system.
2.2.3
Connection to the tractor
The hydraulic drive should be connected to the tractor as
follows:
• Connect the pressure pipe to one of the tractor valves.
Connect the return hose to a pressureless return pipe {less
than 500 kPa (5 bar)} on the tractor. If the return pipe is
connected to a valve and/or pipe with too narrow a
diameter, the hydraulic motor may be damaged.
• Regulate the oil flow by means of the turning button (B,
fig.1) in such a way that the fan turns at a speed of 3000
rpm as a minimum and 3500 rpm as a maximum.
The engine speed should be adjusted to working speed. Use
the control valve (B) to so adjust the fan speed that it just
remains within the working area without an alarm being
generated by the POLYTRONIC control system for fan
speed too low or too high.
43
7
B
A
!
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